xref: /openbmc/linux/drivers/scsi/snic/snic_disc.c (revision d9fd5a71)
1 /*
2  * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
3  *
4  * This program is free software; you may redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 2 of the License.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
9  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
10  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
11  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
12  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
13  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
14  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
15  * SOFTWARE.
16  */
17 
18 #include <linux/errno.h>
19 #include <linux/mempool.h>
20 
21 #include <scsi/scsi_tcq.h>
22 
23 #include "snic_disc.h"
24 #include "snic.h"
25 #include "snic_io.h"
26 
27 
28 /* snic target types */
29 static const char * const snic_tgt_type_str[] = {
30 	[SNIC_TGT_DAS] = "DAS",
31 	[SNIC_TGT_SAN] = "SAN",
32 };
33 
34 static inline const char *
35 snic_tgt_type_to_str(int typ)
36 {
37 	return ((typ > SNIC_TGT_NONE && typ <= SNIC_TGT_SAN) ?
38 		 snic_tgt_type_str[typ] : "Unknown");
39 }
40 
41 static const char * const snic_tgt_state_str[] = {
42 	[SNIC_TGT_STAT_INIT]	= "INIT",
43 	[SNIC_TGT_STAT_ONLINE]	= "ONLINE",
44 	[SNIC_TGT_STAT_OFFLINE]	= "OFFLINE",
45 	[SNIC_TGT_STAT_DEL]	= "DELETION IN PROGRESS",
46 };
47 
48 const char *
49 snic_tgt_state_to_str(int state)
50 {
51 	return ((state >= SNIC_TGT_STAT_INIT && state <= SNIC_TGT_STAT_DEL) ?
52 		snic_tgt_state_str[state] : "UNKNOWN");
53 }
54 
55 /*
56  * Initiate report_tgt req desc
57  */
58 static void
59 snic_report_tgt_init(struct snic_host_req *req, u32 hid, u8 *buf, u32 len,
60 		     dma_addr_t rsp_buf_pa, ulong ctx)
61 {
62 	struct snic_sg_desc *sgd = NULL;
63 
64 
65 	snic_io_hdr_enc(&req->hdr, SNIC_REQ_REPORT_TGTS, 0, SCSI_NO_TAG, hid,
66 			1, ctx);
67 
68 	req->u.rpt_tgts.sg_cnt = cpu_to_le16(1);
69 	sgd = req_to_sgl(req);
70 	sgd[0].addr = cpu_to_le64(rsp_buf_pa);
71 	sgd[0].len = cpu_to_le32(len);
72 	sgd[0]._resvd = 0;
73 	req->u.rpt_tgts.sg_addr = cpu_to_le64((ulong)sgd);
74 }
75 
76 /*
77  * snic_queue_report_tgt_req: Queues report target request.
78  */
79 static int
80 snic_queue_report_tgt_req(struct snic *snic)
81 {
82 	struct snic_req_info *rqi = NULL;
83 	u32 ntgts, buf_len = 0;
84 	u8 *buf = NULL;
85 	dma_addr_t pa = 0;
86 	int ret = 0;
87 
88 	rqi = snic_req_init(snic, 1);
89 	if (!rqi) {
90 		ret = -ENOMEM;
91 		goto error;
92 	}
93 
94 	if (snic->fwinfo.max_tgts)
95 		ntgts = min_t(u32, snic->fwinfo.max_tgts, snic->shost->max_id);
96 	else
97 		ntgts = snic->shost->max_id;
98 
99 	/* Allocate Response Buffer */
100 	SNIC_BUG_ON(ntgts == 0);
101 	buf_len = ntgts * sizeof(struct snic_tgt_id) + SNIC_SG_DESC_ALIGN;
102 
103 	buf = kzalloc(buf_len, GFP_KERNEL|GFP_DMA);
104 	if (!buf) {
105 		snic_req_free(snic, rqi);
106 		SNIC_HOST_ERR(snic->shost, "Resp Buf Alloc Failed.\n");
107 
108 		ret = -ENOMEM;
109 		goto error;
110 	}
111 
112 	SNIC_BUG_ON((((unsigned long)buf) % SNIC_SG_DESC_ALIGN) != 0);
113 
114 	pa = dma_map_single(&snic->pdev->dev, buf, buf_len, DMA_FROM_DEVICE);
115 	if (dma_mapping_error(&snic->pdev->dev, pa)) {
116 		SNIC_HOST_ERR(snic->shost,
117 			      "Rpt-tgt rspbuf %p: PCI DMA Mapping Failed\n",
118 			      buf);
119 		kfree(buf);
120 		snic_req_free(snic, rqi);
121 		ret = -EINVAL;
122 
123 		goto error;
124 	}
125 
126 
127 	SNIC_BUG_ON(pa == 0);
128 	rqi->sge_va = (ulong) buf;
129 
130 	snic_report_tgt_init(rqi->req,
131 			     snic->config.hid,
132 			     buf,
133 			     buf_len,
134 			     pa,
135 			     (ulong)rqi);
136 
137 	snic_handle_untagged_req(snic, rqi);
138 
139 	ret = snic_queue_wq_desc(snic, rqi->req, rqi->req_len);
140 	if (ret) {
141 		dma_unmap_single(&snic->pdev->dev, pa, buf_len,
142 				 DMA_FROM_DEVICE);
143 		kfree(buf);
144 		rqi->sge_va = 0;
145 		snic_release_untagged_req(snic, rqi);
146 		SNIC_HOST_ERR(snic->shost, "Queuing Report Tgts Failed.\n");
147 
148 		goto error;
149 	}
150 
151 	SNIC_DISC_DBG(snic->shost, "Report Targets Issued.\n");
152 
153 	return ret;
154 
155 error:
156 	SNIC_HOST_ERR(snic->shost,
157 		      "Queuing Report Targets Failed, err = %d\n",
158 		      ret);
159 	return ret;
160 } /* end of snic_queue_report_tgt_req */
161 
162 /* call into SML */
163 static void
164 snic_scsi_scan_tgt(struct work_struct *work)
165 {
166 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, scan_work);
167 	struct Scsi_Host *shost = dev_to_shost(&tgt->dev);
168 	unsigned long flags;
169 
170 	SNIC_HOST_INFO(shost, "Scanning Target id 0x%x\n", tgt->id);
171 	scsi_scan_target(&tgt->dev,
172 			 tgt->channel,
173 			 tgt->scsi_tgt_id,
174 			 SCAN_WILD_CARD,
175 			 SCSI_SCAN_RESCAN);
176 
177 	spin_lock_irqsave(shost->host_lock, flags);
178 	tgt->flags &= ~SNIC_TGT_SCAN_PENDING;
179 	spin_unlock_irqrestore(shost->host_lock, flags);
180 } /* end of snic_scsi_scan_tgt */
181 
182 /*
183  * snic_tgt_lookup :
184  */
185 static struct snic_tgt *
186 snic_tgt_lookup(struct snic *snic, struct snic_tgt_id *tgtid)
187 {
188 	struct list_head *cur, *nxt;
189 	struct snic_tgt *tgt = NULL;
190 
191 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
192 		tgt = list_entry(cur, struct snic_tgt, list);
193 		if (tgt->id == le32_to_cpu(tgtid->tgt_id))
194 			return tgt;
195 		tgt = NULL;
196 	}
197 
198 	return tgt;
199 } /* end of snic_tgt_lookup */
200 
201 /*
202  * snic_tgt_dev_release : Called on dropping last ref for snic_tgt object
203  */
204 void
205 snic_tgt_dev_release(struct device *dev)
206 {
207 	struct snic_tgt *tgt = dev_to_tgt(dev);
208 
209 	SNIC_HOST_INFO(snic_tgt_to_shost(tgt),
210 		       "Target Device ID %d (%s) Permanently Deleted.\n",
211 		       tgt->id,
212 		       dev_name(dev));
213 
214 	SNIC_BUG_ON(!list_empty(&tgt->list));
215 	kfree(tgt);
216 }
217 
218 /*
219  * snic_tgt_del : work function to delete snic_tgt
220  */
221 static void
222 snic_tgt_del(struct work_struct *work)
223 {
224 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, del_work);
225 	struct Scsi_Host *shost = snic_tgt_to_shost(tgt);
226 
227 	if (tgt->flags & SNIC_TGT_SCAN_PENDING)
228 		scsi_flush_work(shost);
229 
230 	/* Block IOs on child devices, stops new IOs */
231 	scsi_target_block(&tgt->dev);
232 
233 	/* Cleanup IOs */
234 	snic_tgt_scsi_abort_io(tgt);
235 
236 	/* Unblock IOs now, to flush if there are any. */
237 	scsi_target_unblock(&tgt->dev, SDEV_TRANSPORT_OFFLINE);
238 
239 	/* Delete SCSI Target and sdevs */
240 	scsi_remove_target(&tgt->dev);  /* ?? */
241 	device_del(&tgt->dev);
242 	put_device(&tgt->dev);
243 } /* end of snic_tgt_del */
244 
245 /* snic_tgt_create: checks for existence of snic_tgt, if it doesn't
246  * it creates one.
247  */
248 static struct snic_tgt *
249 snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid)
250 {
251 	struct snic_tgt *tgt = NULL;
252 	unsigned long flags;
253 	int ret;
254 
255 	tgt = snic_tgt_lookup(snic, tgtid);
256 	if (tgt) {
257 		/* update the information if required */
258 		return tgt;
259 	}
260 
261 	tgt = kzalloc(sizeof(*tgt), GFP_KERNEL);
262 	if (!tgt) {
263 		SNIC_HOST_ERR(snic->shost, "Failure to allocate snic_tgt.\n");
264 		ret = -ENOMEM;
265 
266 		return tgt;
267 	}
268 
269 	INIT_LIST_HEAD(&tgt->list);
270 	tgt->id = le32_to_cpu(tgtid->tgt_id);
271 	tgt->channel = 0;
272 
273 	SNIC_BUG_ON(le16_to_cpu(tgtid->tgt_type) > SNIC_TGT_SAN);
274 	tgt->tdata.typ = le16_to_cpu(tgtid->tgt_type);
275 
276 	/*
277 	 * Plugging into SML Device Tree
278 	 */
279 	tgt->tdata.disc_id = 0;
280 	tgt->state = SNIC_TGT_STAT_INIT;
281 	device_initialize(&tgt->dev);
282 	tgt->dev.parent = get_device(&snic->shost->shost_gendev);
283 	tgt->dev.release = snic_tgt_dev_release;
284 	INIT_WORK(&tgt->scan_work, snic_scsi_scan_tgt);
285 	INIT_WORK(&tgt->del_work, snic_tgt_del);
286 	switch (tgt->tdata.typ) {
287 	case SNIC_TGT_DAS:
288 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
289 			     snic->shost->host_no, tgt->channel, tgt->id);
290 		break;
291 
292 	case SNIC_TGT_SAN:
293 		dev_set_name(&tgt->dev, "snic_san_tgt:%d:%d-%d",
294 			     snic->shost->host_no, tgt->channel, tgt->id);
295 		break;
296 
297 	default:
298 		SNIC_HOST_INFO(snic->shost, "Target type Unknown Detected.\n");
299 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
300 			     snic->shost->host_no, tgt->channel, tgt->id);
301 		break;
302 	}
303 
304 	spin_lock_irqsave(snic->shost->host_lock, flags);
305 	list_add_tail(&tgt->list, &snic->disc.tgt_list);
306 	tgt->scsi_tgt_id = snic->disc.nxt_tgt_id++;
307 	tgt->state = SNIC_TGT_STAT_ONLINE;
308 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
309 
310 	SNIC_HOST_INFO(snic->shost,
311 		       "Tgt %d, type = %s detected. Adding..\n",
312 		       tgt->id, snic_tgt_type_to_str(tgt->tdata.typ));
313 
314 	ret = device_add(&tgt->dev);
315 	if (ret) {
316 		SNIC_HOST_ERR(snic->shost,
317 			      "Snic Tgt: device_add, with err = %d\n",
318 			      ret);
319 
320 		put_device(&snic->shost->shost_gendev);
321 		kfree(tgt);
322 		tgt = NULL;
323 
324 		return tgt;
325 	}
326 
327 	SNIC_HOST_INFO(snic->shost, "Scanning %s.\n", dev_name(&tgt->dev));
328 
329 	scsi_queue_work(snic->shost, &tgt->scan_work);
330 
331 	return tgt;
332 } /* end of snic_tgt_create */
333 
334 /* Handler for discovery */
335 void
336 snic_handle_tgt_disc(struct work_struct *work)
337 {
338 	struct snic *snic = container_of(work, struct snic, tgt_work);
339 	struct snic_tgt_id *tgtid = NULL;
340 	struct snic_tgt *tgt = NULL;
341 	unsigned long flags;
342 	int i;
343 
344 	spin_lock_irqsave(&snic->snic_lock, flags);
345 	if (snic->in_remove) {
346 		spin_unlock_irqrestore(&snic->snic_lock, flags);
347 		kfree(snic->disc.rtgt_info);
348 
349 		return;
350 	}
351 	spin_unlock_irqrestore(&snic->snic_lock, flags);
352 
353 	mutex_lock(&snic->disc.mutex);
354 	/* Discover triggered during disc in progress */
355 	if (snic->disc.req_cnt) {
356 		snic->disc.state = SNIC_DISC_DONE;
357 		snic->disc.req_cnt = 0;
358 		mutex_unlock(&snic->disc.mutex);
359 		kfree(snic->disc.rtgt_info);
360 		snic->disc.rtgt_info = NULL;
361 
362 		SNIC_HOST_INFO(snic->shost, "tgt_disc: Discovery restart.\n");
363 		/* Start Discovery Again */
364 		snic_disc_start(snic);
365 
366 		return;
367 	}
368 
369 	tgtid = (struct snic_tgt_id *)snic->disc.rtgt_info;
370 
371 	SNIC_BUG_ON(snic->disc.rtgt_cnt == 0 || tgtid == NULL);
372 
373 	for (i = 0; i < snic->disc.rtgt_cnt; i++) {
374 		tgt = snic_tgt_create(snic, &tgtid[i]);
375 		if (!tgt) {
376 			int buf_sz = snic->disc.rtgt_cnt * sizeof(*tgtid);
377 
378 			SNIC_HOST_ERR(snic->shost, "Failed to create tgt.\n");
379 			snic_hex_dump("rpt_tgt_rsp", (char *)tgtid, buf_sz);
380 			break;
381 		}
382 	}
383 
384 	snic->disc.rtgt_info = NULL;
385 	snic->disc.state = SNIC_DISC_DONE;
386 	mutex_unlock(&snic->disc.mutex);
387 
388 	SNIC_HOST_INFO(snic->shost, "Discovery Completed.\n");
389 
390 	kfree(tgtid);
391 } /* end of snic_handle_tgt_disc */
392 
393 
394 int
395 snic_report_tgt_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
396 {
397 
398 	u8 typ, cmpl_stat;
399 	u32 cmnd_id, hid, tgt_cnt = 0;
400 	ulong ctx;
401 	struct snic_req_info *rqi = NULL;
402 	struct snic_tgt_id *tgtid;
403 	int i, ret = 0;
404 
405 	snic_io_hdr_dec(&fwreq->hdr, &typ, &cmpl_stat, &cmnd_id, &hid, &ctx);
406 	rqi = (struct snic_req_info *) ctx;
407 	tgtid = (struct snic_tgt_id *) rqi->sge_va;
408 
409 	tgt_cnt = le32_to_cpu(fwreq->u.rpt_tgts_cmpl.tgt_cnt);
410 	if (tgt_cnt == 0) {
411 		SNIC_HOST_ERR(snic->shost, "No Targets Found on this host.\n");
412 		ret = 1;
413 
414 		goto end;
415 	}
416 
417 	/* printing list of targets here */
418 	SNIC_HOST_INFO(snic->shost, "Target Count = %d\n", tgt_cnt);
419 
420 	SNIC_BUG_ON(tgt_cnt > snic->fwinfo.max_tgts);
421 
422 	for (i = 0; i < tgt_cnt; i++)
423 		SNIC_HOST_INFO(snic->shost,
424 			       "Tgt id = 0x%x\n",
425 			       le32_to_cpu(tgtid[i].tgt_id));
426 
427 	/*
428 	 * Queue work for further processing,
429 	 * Response Buffer Memory is freed after creating targets
430 	 */
431 	snic->disc.rtgt_cnt = tgt_cnt;
432 	snic->disc.rtgt_info = (u8 *) tgtid;
433 	queue_work(snic_glob->event_q, &snic->tgt_work);
434 	ret = 0;
435 
436 end:
437 	/* Unmap Response Buffer */
438 	snic_pci_unmap_rsp_buf(snic, rqi);
439 	if (ret)
440 		kfree(tgtid);
441 
442 	rqi->sge_va = 0;
443 	snic_release_untagged_req(snic, rqi);
444 
445 	return ret;
446 } /* end of snic_report_tgt_cmpl_handler */
447 
448 /* Discovery init fn */
449 void
450 snic_disc_init(struct snic_disc *disc)
451 {
452 	INIT_LIST_HEAD(&disc->tgt_list);
453 	mutex_init(&disc->mutex);
454 	disc->disc_id = 0;
455 	disc->nxt_tgt_id = 0;
456 	disc->state = SNIC_DISC_INIT;
457 	disc->req_cnt = 0;
458 	disc->rtgt_cnt = 0;
459 	disc->rtgt_info = NULL;
460 	disc->cb = NULL;
461 } /* end of snic_disc_init */
462 
463 /* Discovery, uninit fn */
464 void
465 snic_disc_term(struct snic *snic)
466 {
467 	struct snic_disc *disc = &snic->disc;
468 
469 	mutex_lock(&disc->mutex);
470 	if (disc->req_cnt) {
471 		disc->req_cnt = 0;
472 		SNIC_SCSI_DBG(snic->shost, "Terminating Discovery.\n");
473 	}
474 	mutex_unlock(&disc->mutex);
475 }
476 
477 /*
478  * snic_disc_start: Discovery Start ...
479  */
480 int
481 snic_disc_start(struct snic *snic)
482 {
483 	struct snic_disc *disc = &snic->disc;
484 	unsigned long flags;
485 	int ret = 0;
486 
487 	SNIC_SCSI_DBG(snic->shost, "Discovery Start.\n");
488 
489 	spin_lock_irqsave(&snic->snic_lock, flags);
490 	if (snic->in_remove) {
491 		spin_unlock_irqrestore(&snic->snic_lock, flags);
492 		SNIC_ERR("snic driver removal in progress ...\n");
493 		ret = 0;
494 
495 		return ret;
496 	}
497 	spin_unlock_irqrestore(&snic->snic_lock, flags);
498 
499 	mutex_lock(&disc->mutex);
500 	if (disc->state == SNIC_DISC_PENDING) {
501 		disc->req_cnt++;
502 		mutex_unlock(&disc->mutex);
503 
504 		return ret;
505 	}
506 	disc->state = SNIC_DISC_PENDING;
507 	mutex_unlock(&disc->mutex);
508 
509 	ret = snic_queue_report_tgt_req(snic);
510 	if (ret)
511 		SNIC_HOST_INFO(snic->shost, "Discovery Failed, err=%d.\n", ret);
512 
513 	return ret;
514 } /* end of snic_disc_start */
515 
516 /*
517  * snic_disc_work :
518  */
519 void
520 snic_handle_disc(struct work_struct *work)
521 {
522 	struct snic *snic = container_of(work, struct snic, disc_work);
523 	int ret = 0;
524 
525 	SNIC_HOST_INFO(snic->shost, "disc_work: Discovery\n");
526 
527 	ret = snic_disc_start(snic);
528 	if (ret)
529 		goto disc_err;
530 
531 disc_err:
532 	SNIC_HOST_ERR(snic->shost,
533 		      "disc_work: Discovery Failed w/ err = %d\n",
534 		      ret);
535 } /* end of snic_disc_work */
536 
537 /*
538  * snic_tgt_del_all : cleanup all snic targets
539  * Called on unbinding the interface
540  */
541 void
542 snic_tgt_del_all(struct snic *snic)
543 {
544 	struct snic_tgt *tgt = NULL;
545 	struct list_head *cur, *nxt;
546 	unsigned long flags;
547 
548 	scsi_flush_work(snic->shost);
549 
550 	mutex_lock(&snic->disc.mutex);
551 	spin_lock_irqsave(snic->shost->host_lock, flags);
552 
553 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
554 		tgt = list_entry(cur, struct snic_tgt, list);
555 		tgt->state = SNIC_TGT_STAT_DEL;
556 		list_del_init(&tgt->list);
557 		SNIC_HOST_INFO(snic->shost, "Tgt %d q'ing for del\n", tgt->id);
558 		queue_work(snic_glob->event_q, &tgt->del_work);
559 		tgt = NULL;
560 	}
561 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
562 	mutex_unlock(&snic->disc.mutex);
563 
564 	flush_workqueue(snic_glob->event_q);
565 } /* end of snic_tgt_del_all */
566